From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40020C4363A for ; Mon, 26 Oct 2020 14:56:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0062E20773 for ; Mon, 26 Oct 2020 14:56:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="woQEvtdr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1782759AbgJZO4P (ORCPT ); Mon, 26 Oct 2020 10:56:15 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:37050 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1781810AbgJZO4N (ORCPT ); Mon, 26 Oct 2020 10:56:13 -0400 Received: by mail-pf1-f193.google.com with SMTP id 126so5904616pfu.4 for ; Mon, 26 Oct 2020 07:56:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=y9ZdVN328O2uwwSHT+BoNnojVOi64nld5Tda2i3ROBA=; b=woQEvtdrgcTt5KtaGjhWCUPSi5xXh9iNMRclvDRN/w23XTX07a197EfeoZ6etseu0z HXL0T0o7N85P/lN88MJhzuImQQEUAV19uolyMnF24miX1HhhOwQN4x1OSwzwcABZippj sx5kYtTF7ynotAqfdIaeuIul+5NLTLcNH+hJZ5Zl0QrxrDp9QpufqvYhP/XCDhvx+qKW ldXpXuvCHSoxZ3uCWj2AU9BS2PV3x4vWCWEVTSbazHORQVQBMXia8+x+c6Ixdb4bsFrp 4qa3zzyXPfaUUWH9vKMn/vx/Isj4VcNou4jTwTkZy6REvM7nlsw0BxOwKxHDX80gUb6M AqHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=y9ZdVN328O2uwwSHT+BoNnojVOi64nld5Tda2i3ROBA=; b=cbBezHRW4570tzHRJfaD/c/6Q0Gfc3f+k9M2tRd/L6UlGjkfTlk6N6SwVQCj6Jtl/O j1d5CDHN54t6O0uPVj3lrVu9S0GAr6FJoMlbd3UZzy2m4K5uWNIrANVAfx05e0lAX9Y6 i1y4hhGrA+nJpLN2lBe7CGihHTN1cUzrdqZ5zhKyVFRrfGwyaaRdy/qUOHlcJEGtMAZ0 AIMJLIPUmsQsBi6+TkF+FVkgCuyOVso/FWzgashBHH0X97o2vaR6AESh6oLdcYDusW72 VrnQfRDaGB0jQ0UABPyRZKZE790J/EbbGMIIrKEYpyj73FZDi+cV/P4PNORGLBY96zQ7 gRpg== X-Gm-Message-State: AOAM5336mTOZ2v01YBnAJVdnCx1+YCA3bbwYgrnCRmU0eugRXD2RNb97 BuvJdnWZ4eYVfdPZW/AajMjHkw== X-Google-Smtp-Source: ABdhPJybtxEw8eg2MrMPnbUEKzS1LAsNT2c0RtK4JcGJiJczRjV0Xm8NBFRBQb7sIRhVCjvqm2TQ+w== X-Received: by 2002:a65:67d0:: with SMTP id b16mr17133830pgs.335.1603724172489; Mon, 26 Oct 2020 07:56:12 -0700 (PDT) Received: from localhost.localdomain ([103.136.220.89]) by smtp.gmail.com with ESMTPSA id x123sm12042726pfb.212.2020.10.26.07.56.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Oct 2020 07:56:11 -0700 (PDT) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v2 19/19] mm/hugetlb: Add BUILD_BUG_ON to catch invalid usage of tail struct page Date: Mon, 26 Oct 2020 22:51:14 +0800 Message-Id: <20201026145114.59424-20-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201026145114.59424-1-songmuchun@bytedance.com> References: <20201026145114.59424-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are only `RESERVE_VMEMMAP_SIZE / sizeof(struct page)` struct pages can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON to catch this invalid usage of tail struct page. Signed-off-by: Muchun Song --- mm/hugetlb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 029b00ed52ed..b196373a2a39 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3955,6 +3955,8 @@ static int __init hugetlb_init(void) #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page)); + BUILD_BUG_ON(NR_USED_SUBPAGE >= + RESERVE_VMEMMAP_SIZE / sizeof(struct page)); #endif if (!hugepages_supported()) { -- 2.20.1